Nominal Area Choropleth Map

http://news.bbc.co.uk/2/hi/middle_east/6423691.stm
A nominal area choropleth map is a thematic map that displays areal data. These maps use different colors or patterns to distinguish between certain areas or regions. The data that is represented is nominal data, meaning there is no ranking order for each category, so therefore a rainbow of different colors is many times used. These maps are useful for comparing measurements or data between different states or regions.